Loader with swivel clam gripper



April 957 P. E. LA TENDRESSE 2,788,143

LOADER WITH SWIVEL CLAM GRIPPER 2 Sheets-Sheet 1 Filed May 12, 195.3

April 9, 1957 P. E. LA TENDRESSE 7 2,788,143

' LOADER WITH SWIVEL CLAM GRIPPER Filed May 12, 1953 Z SheetS-Sheet 2 United States Patent LOADER WITH SWIVEL CLAM GRIPPER Philip E. La Tendresse, Baraga, Mich.

Application May 12, 1953, Serial No. 354,616

3 Claims. (Cl. 214-147) Although loaders with clam grippers have been known heretofore, they have not been as versatile as might be desired. According to the present invention, extreme versatility is provided by providing means for producing a wide variety of movements of the clam gripper. In the preferred form, a gripper can swivel about an axis which is ordinarily vertical, it can be tipped to a rather steep angle, it can be raised, and it can be moved forwardly in a reaching motion.

This application is in part a continuation of my copending application, Serial No. 258,246.

Additional objects and advantages of the invention will be apparent from the following description and from the drawings.

Designation of figures Fig. 1 shows a side elevation of the apparatus chosen for illustration of this invention, one position of the parts being shown in full lines and other positions being shown in broken lines, and logs being shown in the relationship they might assume with respect to the clam gripper in the various positions.

Fig. 2 is a fragmentary sectional view taken along a plane perpendicular to the axis of swivelling of the clam gripper, and a little above the boom, looking toward the boom.

Fig. 3 is a fragmentary sectional view taken approximately along an axial plane with reference to the axis of swivelling, and approximately along the line 3-3 of Fig. 2.

General description of the invention As seen best in Fig. 1, a clam 11 is swivelly carried by a tilt frame 12, which is pivotally carried by boom 13, which in turn is pivoted to the upper end of link frame 14, the lower end of which is pivoted to the rear end of main frame 15 of vehicle 16. The swivelling is controlled by a reversible motor 17, which operates through mechanism to be described. The tilting of tilt frame 12 with respect to boom 13 is controlled by a hydraulic cylinder 18. The raising and lowering of the boom 13 is controlled by a hydraulic cylinder 19. The boom 13 is made to reach forwardly or retract by a hydraulic cylinder 21 which pivots link 14. Cylinders 19 and 21, seen on the near side of the vehicle 17, are matched by like cylinders on the far side of the vehicle. This is stated on the assumption that the boom 13 is of the preferred form comprising two widely separated longitudinal members which lie along opposite sides of the cab 22 and may on occasion he guided by the cab.

Tilt frame As seen best in Fig. 2, the tilt frame 12 is journalled at its opposite sides to the ends of the longitudinal members of boom 13. The tilt frame includes a transverse beam 26, which carries at its ends trunnion pins 27. Upstanding from the beam 26 is an inverted U-frame 28. A hydraulic cylinder 29 is carried by the U-frame 28 for opening and closing the clam gripper as will be de- 2,788,143 Patented Apr. 9, 1957 Description of swivelling features The two clam halves 34 are pivoted to a yoke 36, as seen best in the lower dotted line of Fig. 1. As seen best in Fig. 3, the yoke 36 is rigidly secured, together with sprocket 37, to a swivel hub 39. Through suitable roller bearings, preferably arranged in widely separated rings, the hub 39 is swivelly carried by spindle 41, which is rigidly carried by beam 26.

A chain 42 extends around sprockets 37 for driving the sprocket 37 to swivel the clam. The preferred drive arrangement is best seen in Fig. 2. The swivelling drive is derved from motor 17 carried by a bracket 44 secured rigidly to beam 26. The motor 17 is a reversible motor and could be electric but it is preferably hydraulic. it drives a sprocket 46. The sprocket 46 drives a chain 47 which extends around a sprocket 48 of an idler pair. The other sprocket of this pair, sprocket 49, rotates with sprocket 48 and drives chain 42. As previously noted, chain 42 drives sprocket 37 to swivel the clam. The sprocket pair 48 and 49 is suitably journalled by a bracket 51 which is rigidly carried by the beam 26.

The swivelling of the clam is unlimited. it may be swivelled a full 360 and, if occasion should arise, could continuously be swivelled in one direction.

The swivelling does not interfere with the opening and closing of the clam. As best seen in the lower dotted lines of Fig. 1, the two clam halves 34 are controlled by links 53. As seen in Fig. 3, the upper ends of these links 53 are pivoted to a coupler 54 carried at the lower end of piston rod 56 of cyilnder 29. Because cylinder 29 is concentric with respect to the axis of spindle 41, the swivelling of the clam has no effect on the operation of cylinder 29. The piston rod 56 may swivel within the cylinder 29, or it may have a swivel connection with the head or coupler 54.

The clam halves 34 are preferably geared together, so that they are always symmetrically disposed with respect to yoke 36. This keeps piston rod 56 centered in spindle 41. As a matter of fact, minor departures of rod 56 from its intended centered position can be tolerated because cylinder 29 is mounted by being pivoted at its top.

Examples of operation The swivelling clam can be used in a number of widely varying operations. A pile of logs can be approached from the most convenient angle, and the clam turned until its gripper axis is parallel with the logs, whereupon it may be thrust down among the logs and then closed. Often it will be desirable to pick up the logs when their sides are facing the vehicle, and then turn the clam through in order to deposit the logs with their ends facing the vehicle. There are occasions with high piles of logs when the only convenient way to seize the upper log is to tilt the gripper approximately as seen in full lines in Fig. 1 so as to clear the pile or nearly clear the pile and work the gripper in from the top. For this operation it will usually be necessary to have the clam turned to the position shown in full lines in Fig. 1. On other occasions it may be desirable to use the clam for dragging logs from a pile or raking them along the ground to a convenient position to lift them. For this operation it will usually be necessary to have the clam turned to the position seen in Fig. l, in the lower dotted lines thereof. The forward movement of the boom 13, together with the forward tilting of the clam 11 gives the vehicle an exceptionally long reach.

Although the swivelled clam is greatly preferred, a nonswivelling clam would have some of the advantages here indicated. For example, if disposed to have its halves meet along a plane perpendicular to the tilt axis of tilt frame 12, it could be used as shown in full lines in Fig. 1.

The disclosure of Serial No. 258,246 is incorporated herein by reference.

I claim:

1. A loader including a boom, a tilt frame pivoted to the forward end of the boom to pivot about a horizontal tilt axis, power means for tilting the tilt frame, said tilt frame including a spindle disposed with its axis perpendicular to said tilt axis, a yoke swivelled on said spindle and extending away from the tilt axis of the tilt frame, a clam comprising clam halves pivoted to said yoke, and means for opening and closing the clam, in cluding a rod extending coaxially of the spindle, and a cylinder coaxial therewith for operating the rod, said cylinder being carried by the tilt frame and said rod being carried with the yoke so that swivelling of the clam is accommodated by swivelling between the cylinder and rod.

2. A loader including a clam gripper having clam halves each with a set of spaced widely bowed arms, and having open sides for gripping a group of logs between the set of arms, a tilt frame including a unitary base portion, and a swivel portion swiveled to the base portion and to which the clam halves are pivoted at points closer to the boom than the distance from said points to the tips of the clam halves, and corelated to maintain the clam axis at a fixed angle to the swivel portion, a vertically pivotable boom, to the forward end of which the base portion is pivoted about a horizontal axis movable with the boom to a height raising the gripper, while hanging straight downwardly at least said distance clear above the ground, power means for pivoting the tilt frame through angles at which it can hang downwardly and project somewhat forwardly in all boom positions, power means, acting in a plane which pivots with the tilt frame and is adjacent to the tilting axis, for swivelling the swivel portion through unlimited angularity with power swivelling at all angles, a vehicle, and an upstanding link pivoted to the vehicle at its lower end and at its upper end pivotally carrying the boom, and power means, including a unit connected between the vehicle and the boom and another unit connected between the vehicle and the link, for raising and lowering the boom and for pivoting the link to move the boom forwardly and rearwardly while it holds the clam approximately at a given level.

3. A loader including a clam gripper having clam halves each with a set of spaced widely bowed arms, and having open sides for gripping a group of logs between the set of arms, a tilt frame including a unitary base portion, and a swivel portion swiveled to the base portion and to which the clam halves are pivoted at points closer to the boom than the distance from said points to the tips of the clam halves, and corelated to maintain the clam axis at a fixed angle to the swivel portion, a vertically pivotable boom, to the forward end of which the base portion is pivoted about a horizontal axis movable with the boom to a height raising the gripper, while hanging straight downwardly at least said distance clear above the ground, power means for pivoting the tilt frame through angles at which it can hang downwardly and project somewhat forwardly in all boom positions, power means for swivelling the swivel portion through unlimited angularity' with power swivelling at all angles, a vehicle, and an upstanding link pivoted to the'vehicle at its lower end and at its upper end pivotally carrying the boom, and power means, including a unit connected between the vehicle and the boom and another unit connected between the vehicle and the link, for raising and lowering the boom and for pivoting the link to move the boom forwardly and rearwardly while it holds the clam approximately at a given level, said gripper when hanging straight down in its open position having the terminal portions of its arms vertically disposed, and said boom being manipulatable to lower said axis directly vertically whereby the arms can enter between logs substantially without crowding logs outside of the span of the gripper.

References Cited in the file of this patent UNITED STATES PATENTS 536,756 Meier Apr. 2, 1895 994,506 Falcone June 6, 1911 1,052,367 Neil Feb. 4, 1913 1,327,324 Hecker Jan. 6, 1920 1,371,344 Brackett Mar. 15, 1921 1,518,560 Carroll Dec. 9, 1924 2,474,374 Shattuck June 28, 1949 2,639,826 Welden May 26, 1953 2,651,424 Johnson Sept. 8, 1953 2,725,996 Britton Dec. 6, 1955 

